The concept of TFS in the cloud was first presented back in early 2010, the product team worked hard to preview a constantly evolving solution at the BUILD conference last year and after having completed 31 Sprints today the preview service has been opened for all.

No more invitation codes required, TfsPreview has been made public!

“Since we announced the Team Foundation Service Preview at the BUILD conference last year, we’ve limited the on boarding of new customers by requiring invitation codes to create accounts.  The main reason for this has been to control the growth of the service to make sure it didn’t run away from us and end up with a bad user experience.  In this time period, we’ve continued to work on our infrastructure, performance, scale, monitoring, management and, of course, some cool new features like cloud build. ”   - Brian Harry

Since the service is still in preview, it is free for all… If you haven’t, now is the best time to try out the offering. There is no fixed time line on how long before service becomes chargeable but the terms of service support production use, the service is reliable and the product team committed to carry all of your data forward into production.

“The service will remain in “preview” for a while longer while we work through additional features like data portability, commercial terms, etc but the terms of service support production use, the service is reliable and we expect to carry all of your data forward into production. ”  - Brian Harry

As of today it’s possible to use TFS Preview with VS 2012 RC, VS 2010 SP1, VS 2008 SP1, the service currently does not work with VS 2005, this is something the product team is actively working on.

You can refer to Brian’s announcement blog post here, http://blogs.msdn.com/b/bharry/archive/2012/06/11/team-foundation-service-preview-is-public.aspx